Electrochemical cells with multiple separators, and methods of producing the same

ABSTRACT

Embodiments described herein relate to electrochemical cells with multiple separators, and methods of producing the same. A method of producing an electrochemical cell can include disposing an anode material onto an anode current collector, disposing a first separator on the anode material, disposing a cathode material onto a cathode current collector, disposing a second separator onto the cathode material, and disposing the first separator on the second separator to form the electrochemical cell. The anode material and/or the cathode material can be a semi-solid electrode material including an active material, a conductive material, and a volume of liquid electrolyte. In some embodiments, less than about 10% by volume of the liquid electrolyte evaporates during the forming of the electrochemical cell. In some embodiments, the method can further include wetting the first separator and/or the second separator with an electrolyte solution prior to coupling the first separator to the second separator.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to and benefit of U.S.Provisional Application No. 63/181,721, filed Apr. 29, 2021, andentitled “Electrochemical cells with Multiple Separators and Methods ofProducing the Same,” the entire disclosure of which is incorporatedherein by reference.

TECHNICAL FIELD

Embodiments described herein relate to electrochemical cells withmultiple separators, and methods of producing the same.

BACKGROUND

Electrolyte is added to electrodes during production of electrochemicalcells. Electrolyte is often in the form of an electrolyte solvent withan electrolyte salt dissolved therein. Conventional electrochemical cellproduction processes include forming solid electrodes, placing them in acontainer and adding the electrolyte to the container. However,formation of semi-solid electrodes can include adding an electrolytesolution to an active material and a conductive material to form aslurry. During the production process, the slurry can be moved from onelocation to another, and electrolyte solvent can evaporate from theslurry. This solvent can be costly to replace. Preventing solventevaporation rather than replacing evaporated solvent can significantlyreduce costs associated with production of electrochemical cells.

SUMMARY

Embodiments described herein relate to electrochemical cells withmultiple separators, and methods of producing the same. A method ofproducing an electrochemical cell can include disposing an anodematerial onto an anode current collector, disposing a first separator onthe anode material, disposing a cathode material onto a cathode currentcollector, disposing a second separator onto the cathode material, anddisposing the first separator on the second separator to form theelectrochemical cell. The anode material and/or the cathode material canbe a semi-solid electrode material including an active material, aconductive material, and a volume of liquid electrolyte. In someembodiments, less than about 10% by volume of the liquid electrolyteevaporates during the forming of the electrochemical cell. In someembodiments, the method can further include wetting the first separatorand/or the second separator with an electrolyte solution prior tocoupling the first separator to the second separator. In someembodiments, the wetting is via spraying. In some embodiments, less thanabout 10% by volume of the electrolyte solution evaporates during theforming of the electrochemical cell. In some embodiments, less thanabout 10% of a total volume of a combination of the electrolyte solutionand the liquid electrolyte can evaporate during the forming of theelectrochemical cell. In some embodiments, the first separator and/orthe second separator can be composed of a material with a porosity ofless than about 1%. In some embodiments, the cathode current collector,the cathode material, and the second separator can collectively form acathode, and the method further comprises conveying the cathode along acathode conveyor. In some embodiments, the anode current collector, theanode material, and the first separator can collectively form an anode,and the method further comprises conveying the anode along an anodeconveyor. In some embodiments, the anode conveyor can be the sameconveyor as the cathode conveyor. In some embodiments, the anodeconveyor can be a different conveyor from the cathode conveyor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram an electrochemical cell with multipleseparators, according to an embodiment.

FIG. 2 is an illustration of an electrochemical cell with multipleseparators, according to an embodiment.

FIG. 3 is a block diagram of a method of manufacturing anelectrochemical cell with multiple separators, according to anembodiment.

FIGS. 4A-4C show methods of conveyance of electrodes, according tovarious embodiments.

FIG. 5 is an illustration of an electrochemical cell with multipleseparators, according to an embodiment.

FIG. 6 is an illustration of an electrochemical cell with multipleseparators, according to an embodiment.

FIG. 7 is an illustration of an electrochemical cell with multipleseparators, according to an embodiment.

FIGS. 8A-8B show a comparison between a control electrochemical cellwith a single separator and an electrochemical cell with two separatorsand a layer of hard carbon disposed therebetween.

FIGS. 9A-9B show a comparison between a control electrochemical cellwith a single separator and an electrochemical cell with two separatorsand a layer of hard carbon disposed therebetween.

DETAILED DESCRIPTION

Embodiments described herein relate to multi-separator electrochemicalcells and systems, and methods of manufacturing the same. Separators inelectrochemical cells physically isolate an anode from a cathode so asto prevent short circuits and maintain a voltage difference between theanode and the cathode. Pores in separators allow passage ofelectroactive species therethrough. Separators can have an additionalbenefit of shielding evaporation of electrolyte solution duringproduction.

In some embodiments, electrodes described herein can be semi-solidelectrodes. In comparison to conventional electrodes, semi-solidelectrodes can be made (i) thicker (e.g., greater than about 250 μm—upto about 2,000 μm or even greater) due to the reduced tortuosity andhigher electronic conductivity of semi-solid electrodes, (ii) withhigher loadings of active materials, (iii) with a simplifiedmanufacturing process utilizing less equipment, and (iv) can be operatedbetween a wide range of C-rates while maintaining a substantial portionof their theoretical charge capacity. These relatively thick semi-solidelectrodes decrease the volume, mass and cost contributions of inactivecomponents with respect to active components, thereby enhancing thecommercial appeal of batteries made with the semi-solid electrodes. Insome embodiments, the semi-solid electrodes described herein, arebinderless and/or do not use binders that are used in conventionalbattery manufacturing. Instead, the volume of the electrode normallyoccupied by binders in conventional electrodes, is now occupied, by: 1)electrolyte, which has the effect of decreasing tortuosity andincreasing the total salt available for ion diffusion, therebycountering the salt depletion effects typical of thick conventionalelectrodes when used at high rate, 2) active material, which has theeffect of increasing the charge capacity of the battery, or 3)conductive additive, which has the effect of increasing the electronicconductivity of the electrode, thereby countering the high internalimpedance of thick conventional electrodes. The reduced tortuosity and ahigher electronic conductivity of the semi-solid electrodes describedherein, results in superior rate capability and charge capacity ofelectrochemical cells formed from the semi-solid electrodes.

Since the semi-solid electrodes described herein can be madesubstantially thicker than conventional electrodes, the ratio of activematerials (i.e., the semi-solid cathode and/or anode) to inactivematerials (i.e., the current collector and separator) can be much higherin a battery formed from electrochemical cell stacks that includesemi-solid electrodes relative to a similar battery formed formelectrochemical cell stacks that include conventional electrodes. Thissubstantially increases the overall charge capacity and energy densityof a battery that includes the semi-solid electrodes described herein.The use of semi-solid, binderless electrodes can also be beneficial inthe incorporation of an overcharge protection mechanism, as generatedgas can migrate to the electrode/current collector interface withoutbinder particles inhibiting the movement of the gas within theelectrode.

In some embodiments, the electrode materials described herein can be aflowable semi-solid or condensed liquid composition. A flowablesemi-solid electrode can include a suspension of an electrochemicallyactive material (anodic or cathodic particles or particulates), andoptionally an electronically conductive material (e.g., carbon) in anon-aqueous liquid electrolyte. Said another way, the active electrodeparticles and conductive particles are co-suspended in a liquidelectrolyte to produce a semi-solid electrode. Examples ofelectrochemical cells that include a semi-solid and/or binderlesselectrode material are described in U.S. Pat. No. 8,993,159 entitled,“Semi-solid Electrodes Having High Rate Capability,” filed Apr. 29, 2013(“the '159 patent”), the disclosure of which is incorporated herein byreference in its entirety.

In some embodiments, the electrode materials described herein can be aflowable semi-solid or condensed liquid composition. In someembodiments, a flowable semi-solid electrode can include a suspension ofan electrochemically active material (anodic or cathodic particles orparticulates), and optionally an electronically conductive material(e.g., carbon) in a non-aqueous liquid electrolyte. In some embodiments,the active electrode particles and conductive particles can beco-suspended in an electrolyte to produce a semi-solid electrode. Insome embodiments, electrode materials described herein can includeconventional electrode materials (e.g., including lithium metal).

Semi-solid electrodes have a liquid electrolyte integrated thereinduring a longer portion of the manufacturing process than conventionalelectrodes, which add electrolyte solution after the electrodes arefully formed. In other words, liquid electrolyte is added to conductivematerials and/or active materials to form a semi-solid electrodematerial. While the semi-solid electrode material is undergoing furtherprocessing, liquid electrolyte solvent can evaporate from the semi-solidelectrode material. This evaporation can raise the molarity ofelectrolyte salt in the electrolyte solution, potentially causing saltbuildup. Built-up salt can prevent passage of electroactive speciesthrough the semi-solid electrode material. In other words, movement ofelectroactive species through pores of the semi-solid electrode materialcan be more difficult when salt ions build up and block flow paths.Additionally, evaporation of electrolyte solution can make thesemi-solid electrode material less flowable and/or less malleable.Liquid flow paths within the semi-solid electrode material can dry out,increasing tortuosity of the movements of electroactive species.

While adding electrolyte solvent during production can address some ofthese problems, make-up electrolyte solvent can add significant cost tothe production process. Coupling separators to the anode and/or thecathode during production of the electrochemical cell can aid inreducing evaporation of electrolyte solvent during production. In someembodiments, separators described herein can have geometries and generalproperties the same or substantially similar to those described in PCTApplication US2020/058564 entitled “Electrochemical Cells with SeparatorSeals, and Methods of Manufacturing the Same,” filed Nov. 2, 2020 (“the'564 application”), the disclosure of which is hereby incorporated byreference in its entirety.

FIG. 1 is a block diagram of an electrochemical cell 100 with multipleseparators, according to an embodiment. As shown, the electrochemicalcell 100 includes an anode material 110 disposed on an anode currentcollector 120 and a cathode material 130 disposed on a cathode currentcollector 140, with a first separator 150 a and a second separator 150 b(collectively referred to as “separators 150”) disposed therebetween. Insome embodiments, the anode material 110 and/or the cathode material 130can include a semi-solid electrode material. In some embodiments, theanode material 110 and/or the cathode material 130 can include any ofthe properties of the semi-solid electrodes described in the '159patent.

In some embodiments, the anode material 110 and/or the cathode material130 can include at least about 0.1%, at least about 0.2%, at least about0.3%, at least about 0.4%, at least about 0.5%, at least about 0.6%, atleast about 0.7%, at least about 0.8%, at least about 0.9%, at leastabout 1%, at least about 2%, at least about 3%, at least about 4%, atleast about 5%, at least about 6%, at least about 7%, at least about 8%,at least about 9%, at least about 10%, at least about 11%, at leastabout 12%, at least about 13%, at least about 14%, at least about 15%,at least about 16%, at least about 17%, at least about 18%, at leastabout 19%, at least about 20%, at least about 21%, at least about 22%,at least about 23%, or at least about 24% by volume of liquidelectrolyte solution. In some embodiments, the anode material 110 and/orthe cathode material 130 can include no more than about 25%, no morethan about 24%, no more than about 23%, no more than about 22%, no morethan about 21%, no more than about 20%, no more than about 19%, no morethan about 18%, no more than about 17%, no more than about 16%, no morethan about 15%, no more than about 14%, no more than about 13%, no morethan about 12%, no more than about 11%, no more than about 10%, no morethan about 9%, no more than about 8%, no more than about 7%, no morethan about 6%, no more than about 5%, no more than about 4%, no morethan about 3%, no more than about 2%, no more than about 1%, no morethan about 0.9%, no more than about 0.8%, no more than about 0.7%, nomore than about 0.6%, no more than about 0.5%, no more than about 0.4%,no more than about 0.3%, or no more than about 0.2% by volume of liquidelectrolyte solution.

Combinations of the above-referenced volumetric percentages of liquidelectrolyte solution in the anode material 110 and/or the cathodematerial 130 are also possible (e.g., at least about 0.1% and no morethan about 25% or at least about 5% and no more than about 10%),inclusive of all values and ranges therebetween. In some embodiments,the anode material 110 and/or the cathode material 130 can include about0.1%, about 0.2%, about 0.3%, about 0.4%, about 0.5%, about 0.6%, about0.7%, about 0.8%, about 0.9%, about 1%, about 2%, about 3%, about 4%,about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%,about 12%, about 13%, about 14%, about 15%, about 16%, about 17%, about18%, about 19%, about 20%, about 21%, about 22%, about 23%, about 24%,or about 25% by volume of liquid electrolyte solution.

In some embodiments, the anode current collector 120 and/or the cathodecurrent collector 140 can be composed of copper, aluminum, titanium, orother metals that do not form alloys or intermetallic compounds withlithium, carbon, and/or coatings comprising such materials disposed onanother conductor. In some embodiments, the anode current collector 120and/or the cathode current collector 140 can have a thickness of atleast about 1 μm, at least about 5 μm, at least about 10 μm, at leastabout 15 μm, at least about 20 μm, at least about 25 μm, at least about30 μm, at least about 35 μm, at least about 40 μm, or at least about 45μm. In some embodiments, the anode current collector 120 and/or thecathode current collector 140 can have a thickness of no more than about50 μm, no more than about 45 μm, no more than about 40 μm, no more thanabout 35 μm, no more than about 30 μm, no more than about 25 μm, no morethan about 20 μm, no more than about 15 μm, no more than about 10 μm, orno more than about 5 μm. Combinations of the above-referencedthicknesses of the anode current collector 120 and/or the cathodecurrent collector 140 are also possible (e.g., at least about 1 μm andno more than about 50 μm or at least about 10 μm and no more than about30 μm), inclusive of all values and ranges therebetween. In someembodiments, the anode current collector 120 and/or the cathode currentcollector 140 can have a thickness of about 1 μm, about 5 μm, about 10μm, about 15 μm, about 20 μm, about 25 μm, about 30 μm, about 35 μm,about 40 μm, about 45 μm, or about 50 μm.

In some embodiments, the anode material 110 can include a firstelectrolyte and the cathode material 130 can include a secondelectrolyte. In other words, and the anode material 110 can include ananolyte and the cathode material 130 can include a catholyte. In someembodiments, the electrochemical cell 100 can include an anolytedisposed on the anode side of the separators 150. In some embodiments,the electrochemical cell 100 can include a catholyte disposed on thecathode side of the separators 150. In some embodiments, theelectrochemical cell 100 can include a selectively permeable membrane.In some embodiments, the selectively permeable membrane can be disposedbetween the first separator 150 a and the second separator 150 b.Electrochemical cells with anolytes, catholytes, and/or selectivelypermeable membranes are described in U.S. Pat. No. 10,734,672 (“the '672patent”), filed Jan. 8, 2019, and titled, “Electrochemical CellsIncluding Selectively Permeable Membranes, Systems and Methods ofManufacturing the Same,” the disclosure of which is hereby incorporatedby reference in its entirety.

As shown, the first separator 150 a is disposed on the anode material110 while the second separator 150 b is disposed on the cathode material130. In some embodiments, the separators 150 can be disposed on theirrespective electrodes during production of the electrochemical cell 100.In some embodiments, the first separator 150 a and/or the secondseparator 150 b can be composed of polyethylene, polypropylene, highdensity polyethylene, polyethylene terephthalate, polystyrene, athermosetting polymer, hard carbon, a thermosetting resin, a polyimide,a ceramic coated separator, an inorganic separator, cellulose, glassfiber, a polyethylenoxide (PEO) polymer in which a lithium salt iscomplexed to provide lithium conductivity, Nation™ membranes which areproton conductors, or any other suitable separator material, orcombinations thereof. In some embodiments, the first separator 150 aand/or the second separator 150 b can be composed of any of theseparator materials described in the '564 application. In someembodiments, the first separator 150 a can be composed of the samematerial as the second separator 150 b. In some embodiments, the firstseparator 150 a can be composed of a different material from the secondseparator 150 b. In some embodiments, the first separator 150 a and/orthe second separator 150 b can be absent of any framing membersdescribed in the '564 application.

In some embodiments, the first separator 150 a and/or the secondseparator 150 b can have a porosity of at least about 5%, at least about10%, at least about 15%, at least about 20%, at least about 25%, atleast about 30%, at least about 35%, at least about 40%, at least about45%, at least about 50%, at least about 55%, at least about 60%, atleast about 65%, at least about 70%, at least about 75%, at least about80%, or at least about 85%. In some embodiments, the first separator 150a and/or the second separator 150 b can have a porosity of no more thanabout 90%, no more than about 85%, no more than about 80%, no more thanabout 75%, no more than about 70%, no more than about 65%, no more thanabout 60%, no more than about 55%, no more than about 50%, no more thanabout 45%, no more than about 40%, no more than about 35%, no more thanabout 30%, no more than about 25%, no more than about 20%, no more thanabout 15%, or no more than about 10%.

Combinations of the above-referenced porosity percentages of the firstseparator 150 a and/or the second separator 150 b are also possible(e.g., at least about 5% and no more than about 90% or at least about20% and no more than about 40%), inclusive of all values and rangestherebetween. In some embodiments, the first separator 150 a and/or thesecond separator 150 b can have a porosity of about 5%, about 10%, about15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%,about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about80%, about 85%, or about 90%.

In some embodiments, the first separator 150 a can have a differentporosity from the second separator 150 b. In some embodiments, theporosities of the first separator 150 a and the second separator 150 bcan be selected based on the difference between the anolyte and thecatholyte. For example, if the catholyte has a higher vapor pressure andfaster evaporation properties than the anolyte, then the secondseparator 150 b can have a lower porosity than the first separator 150a. The lower porosity of the second separator 150 b can at leastpartially prevent the catholyte from evaporating during production.

In some embodiments, the first separator 150 a can be composed of adifferent material from the second separator 150 b. In some embodiments,the materials of the first separator 150 a and the second separator 150b can be selected to facilitate wettability of the first separator 150 awith the anolyte and the second separator 150 b with the catholyte 150.For example, an ethylene carbonate/propylene carbonate-based catholytecan wet a polyethylene separator better than a polyimide separator,based on the molecular properties of the materials. An ethylenecarbonate/di-methyl carbonate-based anolyte can wet a polyimideseparator better than a polyethylene separator. A full wetting of thefirst separator 150 a and the second separator 150 b can give way tobetter transport of electroactive species via the separators 150. Thistransport can be facilitated particularly well when the first separator150 a physically contacts the second separator 150 b.

In some embodiments, the first separator 150 a and/or the secondseparator 150 b can be absent of separator seals (e.g., separator sealsdescribed in the '564 application). As shown, the electrochemical cell100 includes two separators 150. In some embodiments, theelectrochemical cell 100 can include 3, 4, 5, 6, 7, 8, 9, 10, or morethan about 10 separators 150. In some embodiments, a layer of liquidelectrolyte (not shown) can be disposed between the first separator 150a and the second separator 150 b. A layer of liquid electrolyte canpromote better adhesion between the separators 150.

In some embodiments, the first separator 150 a and/or the secondseparator 150 b can have a thickness of at least about 1 μm, at leastabout 2 μm, at least about 3 μm, at least about 4 μm, at least about 5μm, at least about 6 μm, at least about 7 μm, at least about 8 μm, atleast about 9 μm, at least about 10 μm, at least about 20 μm, at leastabout 30 μm, at least about 40 μm, at least about 50 μm, at least about60 μm, at least about 70 μm, at least about 80 μm, at least about 90 μm,at least about 100 μm, at least about 110 μm, at least about 120 μm, atleast about 130 μm, at least about 140 μm, at least about 150 μm, atleast about 160 μm, at least about 170 μm, at least about 180 μm, or atleast about 190 μm. In some embodiments, the first separator 150 aand/or the second separator 150 b can have a thickness of no more thanabout 200 μm, no more than about 190 μm, no more than about 180 μm, nomore than about 170 μm, no more than about 160 μm, no more than about150 μm, no more than about 140 μm, no more than about 130 μm, no morethan about 120 μm, no more than about 110 μm, no more than about 100 μm,no more than about 90 μm, no more than about 80 μm, no more than about70 μm, no more than about 60 μm, no more than about 50 μm, no more thanabout 40 μm, no more than about 30 μm, no more than about 20 μm, no morethan about 10 μm, no more than about 9 μm, no more than about 8 μm, nomore than about 7 μm, no more than about 6 μm, no more than about 5 μm,no more than about 4 μm, no more than about 3 μm, or no more than about2 μm. Combinations of the above-referenced thicknesses of the firstseparator 150 a and/or the second separator 150 b are also possible(e.g., at least about 1 μm and no more than about 200 μm or at leastabout 50 μm and no more than about 100 μm), inclusive of all values andranges therebetween. In some embodiments, the first separator 150 aand/or the second separator 150 b can have a thickness of about 1 μm,about 2 μm, about 3 μm, about 4 μm, about 5 μm, about 6 μm, about 7 μm,about 8 μm, about 9 μm, about 10 μm, about 20 μm, about 30 μm, about 40μm, about 50 μm, about 60 μm, about 70 μm, about 80 μm, about 90 μm,about 100 μm, about 110 μm, about 120 μm, about 130 μm, about 140 μm,about 150 μm, about 160 μm, about 170 μm, about 180 μm, about 190 μm, orabout 200 μm. In some embodiments, the first separator 150 a can have athickness the same or substantially similar to the thickness of thesecond separator 150 b. In some embodiments, the first separator 150 acan have a thickness greater or less than a thickness of the secondseparator 150 b.

In some embodiments, the first separator 150 a can be coupled to thesecond separator 150 b. In some embodiments, the first separator 150 aand/or the second separator 150 b can be wetted so as to promoteclinging between first separator 150 a and the second separator 150 b.In other words, the first separator 150 a can be held to the secondseparator 150 b via surface tension and/or capillary forces.

In some embodiments, the anode material 110, the anode current collector120, and the first separator 150 a can be packaged in a first container,while the cathode material 130, the cathode current collector 140 andthe second separator 150 b can be packaged in a second container priorto assembly. In other words, the electrochemical cell 100 can beassembled via an anode kit (including the anode material 110, the anodecurrent collector 120, and the first separator 150 a) and a cathode kit(including the cathode material 130, the cathode current collector 140,and the second separator 150 b). The anode material 110, the anodecurrent collector 120, and the first separator 150 a can be removed fromthe first container and the cathode material 130, the cathode currentcollector 140, and the second separator 150 b can be removed from thesecond container. The first separator 150 a can then be disposed on thesecond separator 150 b to form the electrochemical cell 100.

FIG. 2 shows an illustration of an electrochemical cell 200, accordingto an embodiment. As shown, the electrochemical cell 200 includes ananode material 210 disposed on an anode current collector 220, a cathodematerial 230 disposed on a cathode current collector 240, a firstseparator 250 a disposed on the anode material 210, a second separator250 b disposed on the cathode material 230, and an interlayer 260disposed between the first separator 250 a and the second separator 250b. In some embodiments, the anode material 210, the anode currentcollector 220, the cathode material 230, the cathode current collector240, the first separator 250 a, and the second separator 250 b can bethe same or substantially similar to the anode material 110, the anodecurrent collector 120, the cathode material 130, the cathode currentcollector 140, the first separator 150 a, and the second separator 150b, as described above with reference to FIG. 1. Thus, certain aspects ofthe anode material 210, the anode current collector 220, the cathodematerial 230, the cathode current collector 240, the first separator 250a, and the second separator 250 b are not described in greater detailherein.

In some embodiments, the interlayer 260 can include an electrolytelayer. In some embodiments, the electrolyte layer can include a liquidelectrolyte. In some embodiments, the electrolyte layer can include asolid-state electrolyte, for example, to prevent dendrite growth. Insome embodiments, the electrolyte layer can include polyacrylonitrile(PAN). In some embodiments, the electrolyte layer can partially or fullysaturate the first separator 250 a and/or the second separator 250 b(collectively referred to as the separators 250). In some embodiments,the electrolyte layer can aid in bonding the first separator 250 a tothe second separator 250 b. In some embodiments, the electrolyte layercan create a surface tension to bond the first separator 250 a to thesecond separator 250 b. In some embodiments, the electrolyte layer canfacilitate movement of electroactive species between the anode material210 and the cathode material 230.

In some embodiments, the interlayer 260 can have a thickness of at leastabout 500 nm, at least about 1 μm, at least about 2 μm, at least about 3μm, at least about 4 μm, at least about 5 μm, at least about 6 μm, atleast about 7 μm, at least about 8 μm, at least about 9 μm, at leastabout 10 μm, at least about 20 μm, at least about 30 μm, at least about40 μm, at least about 50 μm, at least about 60 μm, at least about 70 μm,at least about 80 μm, or at least about 90 μm. In some embodiments, theinterlayer 260 can have a thickness of no more than about 100 μm, nomore than about 90 μm, no more than about 80 μm, no more than about 70μm, no more than about 60 μm, no more than about 50 μm, no more thanabout 40 μm, no more than about 30 μm, no more than about 20 μm, no morethan about 10 μm, no more than about 9 μm, no more than about 8 μm, nomore than about 7 μm, no more than about 6 μm, no more than about 5 μm,no more than about 4 μm, no more than about 3 μm, no more than about 2μm, or no more than about 1 μm. Combinations of the above-referencedthicknesses of the interlayer 260 are also possible (e.g., at leastabout 500 nm and no more than about 100 μm or at least about 2 μm and nomore than about 30 μm), inclusive of all values and ranges therebetween.In some embodiments, the interlayer 260 can have a thickness of about500 nm, about 1 μm, about 2 μm, about 3 μm, about 4 μm, about 5 μm,about 6 μm, about 7 μm, about 8 μm, about 9 μm, about 10 μm, about 20μm, about 30 μm, about 40 μm, about 50 μm, about 60 μm, about 70 μm,about 80 μm, about 90 μm, or about 100 μm.

In some embodiments, the interlayer 260 can include a semi-solidelectrode layer disposed between the first separator 250 a and thesecond separator 250 b. In some embodiments, the layer of semi-solidelectrode material can be included in addition to the electrolyte layer.In some embodiments, the semi-solid electrode layer between the firstseparator 250 a and the second separator 250 b can include a materialthat reacts with metallic lithium. In some embodiments, the semi-solidelectrode layer between the first separator 250 a and the secondseparator 250 b can include hard carbon, graphite, or any other suitableelectrode material or combinations thereof. In some embodiments, if theanode material 210 begins to form dendrites that penetrate the firstseparator 250 a, the dendritic material can react with the semi-solidelectrode layer between the first separator 250 a and the secondseparator 250 b, such that the dendrites dissipate, thus preventing ashort circuit. In some embodiments, the interlayer 260 may include asingle layer. In some embodiments, the interlayer 260 may include abilayer structure, for example, include a first layer including asemi-solid electrode layer (e.g., a binder-free carbon slurry), and asecond layer including a solid state electrolyte (e.g., LLZO, LLTO,LATP, sulfides, polymer gel electrolytes, etc.).

In some embodiments, the semi-solid electrode layer between the firstseparator 250 a and the second separator 250 b can aid in transportingelectroactive species across the separators 250. The semi-solidelectrode layer between the first separator 250 a and the secondseparator 250 b can provide reduced tortuosity and better lithium iondiffusion compared to conventional electrode materials. The compositionof the semi-solid electrode layer between the first separator 250 a andthe second separator 250 b can be fine-tuned to facilitate ion movementtherethrough.

In some embodiments, the semi-solid electrode layer between the firstseparator 250 a and the second separator 250 b can have catalyticeffects to remove, dissolve, and/or corrode contaminating metal powders(e.g., iron, chromium, nickel, aluminum, copper). In such cases, thesemi-solid electrode layer between the first separator 250 a and thesecond separator 250 b can serve as a metal contamination removingbuffer layer. In some embodiments, the semi-solid electrode layerbetween the first separator 250 a and the second separator 250 b caninclude a non-lithium ion semi-solid slurry with an aligned porestructure, a high surface area, and/or a diffusive structure combinedwith an electrolyte. Such materials can include metal-organic frameworks(MOFs), carbon black, an anode aluminum oxide (AAO) template, and/orsilica. In such cases, the semi-solid electrode layer between the firstseparator 250 a and the second separator 250 b can serve as anelectrolyte reservoir and/or an embedding base for a dendrite-removingcatalyst. Such materials can also improve current distributions in theelectrochemical cell 200. In some embodiments, the dendrite-removingcatalyst can include a metal base and/or a polymer base for thefacilitation of redox reactions. In some embodiments, thedendrite-removing catalyst can include fluorine, sulfide, or any othersuitable catalyst or combinations thereof. In some embodiments, thecatalyst can include a base polymer coating mix or a carbon mix.

In some embodiments, the interlayer 260 can include a conventional(i.e., solid) electrode layer can be disposed between the firstseparator 250 a and the second separator 250 b. In some embodiments, theconventional electrode layer between the first separator 250 a and thesecond separator 250 b can include a binder (e.g., a solid binder or agel binder).

In some embodiments, the interlayer 260 can include a polyolefin, asolid-state electrolyte sheet, and/or a polymer electrolyte sheet. Insome embodiments, the interlayer 260 can include polyacrylonitrile(PAN), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP),poly(methyl methacrylate) (PMMA), polyacrylic acid (PAA), polyethyleneoxide (PEO), or any combination thereof.

In some embodiments, the interlayer 260 can include a cathode. In someembodiments, the cathode in the interlayer 260 can include lithiumtitanate (LTO), hard carbon (HC), and/or any other material with a highimpedance connection. In some embodiments, the LTO can include anelectron-conductive LTO, such as Li_(4+x)Ti₅O₁₂ and/or Li₄Ti₅O_(12−x).In some embodiments, the interlayer 260 can include lithium ironphosphate (LFP) with a high impedance connection. The LFP can beconsidered a safe chemistry for the monitoring of dendrite formation. Ifa dendrite forms in either of the electrodes and penetrates into theinterlayer 260, the dendrite would be consumed. Also, voltage can bemonitored between the interlayer 260 and the anode current collector220, as shown. In some embodiments, voltage can be monitored between theinterlayer 260 and the cathode current collector 240. This voltagemonitoring can detect if a dendrite has reached the interlayer 260.

Measuring voltage between the interlayer 260 and the anode currentcollector 220 and/or the cathode current collector 240 can be a moreefficient method of detecting defects in the electrochemical cell 200than measuring across the entire electrochemical cell 200 (i.e., betweenthe anode current collector 220 and the cathode current collector 240),particularly in modules with multiple cells. In some embodiments,multiple electrochemical cells can be connected in parallel and/orseries to produce a cell module. For example, if a cell has a capacityof 3 Ah, 50 such cells can be connected in parallel to produce acapacity of 150 Ah. In some embodiments, the module can include about 1,about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9,about 10, about 11, about 12, about 13, about 14, about 15, about 16,about 17, about 18, about 19, about 20, about 25, about 30, about 35,about 40, about 45, about 50, about 55, about 60, about 65, about 70,about 75, about 80, about 85, about 90, about 95, or about 100electrochemical cells connected in series and/or parallel, inclusive ofall values and ranges therebetween. In monitoring the voltage across theinterlayer 260 and the anode current collector 220 and/or the cathodecurrent collector 240, the interlayer 260 can serve as a referenceelectrode.

In some embodiments, individual electrochemical cell in a module canhave a capacity of about 0.5 Ah, about 1 Ah, about 2 Ah, about 3 Ah,about 4 Ah, about 5 Ah, about 6 Ah, about 7 Ah, about 8 Ah, about 9 Ah,or about 10 Ah, inclusive of all values and ranges therebetween. In someembodiments, modules described herein can have a capacity of about 10Ah, about 20 Ah, about 30 Ah, about 40 Ah, about 50 Ah, about 60 Ah,about 70 Ah, about 80 Ah, about 90 Ah, about 100 Ah, about 110 Ah, about120 Ah, about 130 Ah, about 140 Ah, about 150 Ah, about 160 Ah, about170 Ah, about 180 Ah, about 190 Ah, about 200 Ah, about 210 Ah, about220 Ah, about 230 Ah, about 240 Ah, about 250 Ah, about 260 Ah, about270 Ah, about 280 Ah, about 290 Ah, or about 300 Ah, inclusive of allvalues and ranges therebetween.

In existing battery management systems (BMS) and cell modules, theability to diagnose the health of each electrochemical cell is limited.To monitor the health of each cell, local voltage and/or currentmeasurements are used to discern small changes in cell voltages. Voltagemeasurements across individual cells offer little direct correlation tothe individual cell health. The addition of differential currentmeasurement in the modules adversely affects the total system complexityand the cost of the measurement systems. Conversely, if the voltagebetween the interlayer 260 and a current collector is measured for eachparallel electrochemical cell, the relative difference of that voltageis a direct measure of the relative health (i.e., impedance) of theanode material 210 and/or the cathode material 230 and relativeimpedance within the electrochemical cell 200 itself. In such anarrangement, it is possible to determine (by direct measurement) if theelectrochemical cell 200 is behaving normally relative to otherelectrochemical cells in a parallel string or pack system. Through massdata collection, trend data from a large collection of electrochemicalcells can be used to coordinate the analysis of a group or lot, orindividual cell serial numbers relative to the larger cell population.

For extremely large format cells, the added complexity to measure anadditional 2-3 differential voltages is lower than the added complexityof adding equivalent high gain current measurement channels, or to addhall effect type sensors, for example. In this way, individual cellhealth of a parallel cell grouping can be directly measured. Additionaldiagnostics to remaining cells connected in series can be evaluatedbased on state-of-charge (SOC) and state-of-health (SOH) algorithms.This allows for early notification of system failures long before faultswould normally be detected. This precision can also allow for aprediction of a date of failure and advanced planning. For example,materials can be positioned properly in an electrochemical cell modulein anticipation of a failure. Additionally, supply chain issues can beconsidered before an original equipment manufacturer (OEM) fleet or anindividual consumer is notified of a fault. After the voltagemeasurement between the interlayer 260 and the anode current collector220 and/or the cathode current collector 240 detects a softshort-circuit, an external short of the cell module can be triggered todischarge.

In some embodiments, the interlayer 260 can prevent dangerous shortcircuit events from dendrite growth via metal contamination (e.g., ironcontamination, zinc contamination, copper contamination) and shuttlingby a buffer layer. In such a case, an iron dendrite can grow and touchhard carbon, graphite, and/or other carbon-containing materials in theinterlayer 260, with the interlayer 260 having a cathode potential. Oncethe iron dendrite touches the hard carbon, graphite, and/or the othercarbon-containing materials in the interlayer 260, the iron dissolvesunder the cathode potential, but the high current moving through theelectrochemical cell 200 persists via a connection through a diode orhigh resistance. When metal contamination is used to prevent dangerousshort circuit events, voltage can be monitored between the interlayer260 and the anode current collector 220 and/or the cathode currentcollector 240 (or between the interlayer 260 and the anode material 210and/or the cathode material 230). In some embodiments, additional safetyactions can be triggered by a BMS if a significant voltage drop (e.g.,at least about 0.5 V, at least about 1 V, at least about 1.5 V, at leastabout 2 V, at least about 2.5 V, at least about 3 V, at least about 3.5V, at least about 4 V, at least about 4.5 V, at least about 5 V,inclusive of all values and ranges therebetween) is detected. In someembodiments, the interlayer 260 may include a tab to enable couplingwith an electrical connection or sensing system external to theelectrochemical cell 200. In some embodiments, multiple electrochemicalcells can be connected in parallel with a tab connected to theinterlayer 260. A diode or high resistance resistor can be connected tomany cathodes (e.g., many tabs connected to cathode current collectors240) and many interlayers (e.g., many tabs connected to interlayers260).

In some embodiments, the interlayer 260 can prevent dangerous shortcircuit events from lithium dendrites via lithium intercalation. Forexample, lithium dendrites can grow and penetrate the first separator250 a or the second separator 250 b and contact hard carbon, graphite,and/or a carbon-containing material in the interlayer 260. Once thelithium dendrite contacts the hard carbon, graphite, and/or thecarbon-containing material in the interlayer 260, the lithiumintercalates into the carbon, graphite, and/or the carbon-containingmaterial. While hard carbon, graphite, and/or any carbon-containingmaterial can facilitate lithium intercalation, any material that reactswith lithium can achieve this lithium intercalation function. In someembodiments, the interlayer 260 can include silicon, aluminum, silver,tungsten, tin, or any combination thereof.

FIG. 3 shows a block diagram of a method 10 of forming anelectrochemical cell, according to an embodiment. As shown, the method10 includes disposing an anode material onto an anode current collectorat step 11 and disposing a first separator onto the anode material atstep 12. The method 10 optionally includes conveying the anode currentcollector, the anode material, and the first separator (collectivelyreferred to as “the anode”) in step 13. The method 10 further includesdisposing a cathode material onto a cathode current collector at step 14and disposing a second separator onto the cathode material at step 15.The method 10 optionally includes conveying the cathode currentcollector, the cathode material, and the second separator (collectivelyreferred to as “the cathode”) at step 16 and wetting the first separatorand/or the second separator at step 17. The method 10 includes couplingthe first separator to the second separator at step 18 to form theelectrochemical cell.

Step 11 includes disposing the anode material onto the anode currentcollector. The anode material and the anode current collector can haveany of the properties of the anode material 110 and the anode currentcollector 120 (e.g., thickness, composition) as described above withreference to FIG. 1. In some embodiments, the anode material can beextruded (e.g., via a twin-screw extruder) onto the anode currentcollector. In some embodiments, the anode material can be dispensed viaa nozzle. In some embodiments, the dispensation of the anode materialcan be via any of the methods described in U.S. provisional application63/115,293 (hereinafter “the '293 application”), entitled, “Methods ofContinuous and Semi-Continuous Production of Electrochemical Cells,”filed Nov. 18, 2020, the entirety of which is incorporated herein byreference. In some embodiments, the dispensation of the anode materialcan be via any of the methods described in U.S. patent publication no.2020/0014025 (hereinafter “the '025 publication), entitled “Continuousand Semi-Continuous Methods of Semi-Solid Electrode and BatteryManufacturing,” filed Jul. 9, 2019, the entirety of which is herebyincorporated by reference.

Step 12 includes disposing the first separator onto the anode material.In some embodiments, the first separator can be pre-soaked or pre-coatedwith electrolyte solution prior to the disposing. In some embodiments,the first separator can be placed onto the anode material by a machine.In some embodiments, the first separator can be placed onto the anodematerial via one or more rollers, conveying separator material. In someembodiments, the separator can be placed onto the anode material via anyof the methods described in the '293 application and/or the '025publication.

Step 13 optionally includes conveying the anode. In some embodiments,the conveying can be on a conveyance device, such as a conveyor belt. Insome embodiments, the conveying can be through a tunnel to limitevaporation of electrolyte solution from the anode. In some embodiments,the anode can be on the conveyance device for at least about 1 second,at least about 5 seconds, at least about 10 seconds, at least about 20seconds, at least about 30 seconds, at least about 40 seconds, at leastabout 50 seconds, at least about 1 minute, at least about 5 minutes, atleast about 10 minutes, at least about 20 minutes, at least about 30minutes, at least about 40 minutes, at least about 50 minutes, at leastabout 1 hour, at least about 2 hours, at least about 3 hours, at leastabout 4 hours, at least about 5 hours, at least about 10 hours, at leastabout 15 hours, or at least about 20 hours. In some embodiments, theanode can be on the conveyance device for no more than about 1 day, nomore than about 20 hours, no more than about 15 hours, no more thanabout 10 hours, no more than about 5 hours, no more than about 4 hours,no more than about 3 hours, no more than about 2 hours, no more thanabout 1 hour, no more than about 50 minutes, no more than about 40minutes, no more than about 30 minutes, no more than about 20 minutes,no more than about 10 minutes, no more than about 5 minutes, no morethan about 4 minutes, no more than about 3 minutes, no more than about 2minutes, no more than about 1 minute, no more than about 50 seconds, nomore than about 40 seconds, no more than about 30 seconds, no more thanabout 20 seconds, no more than about 10 seconds, or no more than about 5seconds.

Combinations of the above-referenced time periods the anode remains onthe conveyance device are also possible (e.g., at least about 1 secondand no more than about 1 day or at least about 5 minutes and no morethan about 2 hours), inclusive of all values and ranges therebetween. Insome embodiments, the anode can be on the conveyance device for about 1second, about 5 seconds, about 10 seconds, about 20 seconds, about 30seconds, about 40 seconds, about 50 seconds, about 1 minute, about 5minutes, about 10 minutes, about 20 minutes, about 30 minutes, about 40minutes, about 50 minutes, about 1 hour, about 2 hours, about 3 hours,about 4 hours, about 5 hours, about 10 hours, about 15 hours, about 20hours, or about 1 day.

In some embodiments, the anode can be conveyed a distance of at leastabout 1 cm, at least about 2 cm, at least about 3 cm, at least about 4cm, at least about 5 cm, at least about 10 cm, at least about 20 cm, atleast about 30 cm, at least about 40 cm, at least about 50 cm, at leastabout 60 cm, at least about 70 cm, at least about 80 cm, at least about90 cm, at least about 1 m, at least about 2 m, at least about 3 m, atleast about 4 m, at least about 5 m, at least about 6 m, at least about7 m, at least about 8 m, at least about 9 m, at least about 10 m, atleast about 20 m, at least about 30 m, at least about 40 m, at leastabout 50 m, at least about 60 m, at least about 70 m, at least about 80m, or at least about 90 m. In some embodiments, the anode can beconveyed a distance of no more than about 100 m, no more than about 90m, no more than about 80 m, no more than about 70 m, no more than about60 m, no more than about 50 m, no more than about 40 m, no more thanabout 30 m, no more than about 20 m, no more than about 10 m, no morethan about 9 m, no more than about 8 m, no more than about 7 m, no morethan about 6 m, no more than about 5 m, no more than about 4 m, no morethan about 3 m, no more than about 2 m, no more than about 1 m, no morethan about 90 cm, no more than about 80 cm, no more than about 70 cm, nomore than about 60 cm, no more than about 50 cm, no more than about 40cm, no more than about 30 cm, no more than about 20 cm, no more thanabout 10 cm, no more than about 9 cm, no more than about 8 cm, no morethan about 7 cm, no more than about 6 cm, no more than about 5 cm, nomore than about 4 cm, no more than about 3 cm, or no more than about 2cm. Combinations of the above-referenced conveyance distances are alsopossible (e.g., at least about 1 cm and no more than about 100 m or atleast about 50 cm and no more than about 20 m), inclusive of all valuesand ranges therebetween. In some embodiments, the anode can be conveyedabout 1 cm, about 2 cm, about 3 cm, about 4 cm, about 5 cm, about 10 cm,about 20 cm, about 30 cm, about 40 cm, about 50 cm, about 60 cm, about70 cm, about 80 cm, about 90 cm, about 1 m, about 2 m, about 3 m, about4 m, about 5 m, about 6 m, about 7 m, about 8 m, about 9 m, about 10 m,about 20 m, about 30 m, about 40 m, about 50 m, about 60 m, about 70 m,about 80 m, about 90 m, or about 100 m.

The separator coating the anode material can prevent electrolyte fromevaporating during conveyance or other portions of the productionprocess. By covering the surface of the anode material distal to theanode current collector a significant percentage of the surface of theanode material (e.g., 90-95%) is not exposed to the surroundingenvironment. Thus, a significant portion of the avenues for evaporationare restricted.

Step 14 includes disposing the cathode material onto the cathode currentcollector. In some embodiments, the dispensation of the cathode materialcan have the same or substantially similar properties to those describedabove with reference to the anode material in step 11. Step 15 includesdisposing the second separator onto the cathode material. In someembodiments, the disposal of the second separator onto the cathodematerial can have the same or substantially similar properties to thosedescribed above with reference to the first separator in step 12.

Step 16 optionally includes conveying the cathode. In some embodiments,the duration and distance of the conveying of the cathode can be thesame or substantially similar to the duration and distance of theconveying of the anode with reference to step 13. In some embodiments,the cathode can be conveyed on the same conveyor as the anode. In someembodiments, the anode can be conveyed on a first conveyor and thecathode can be conveyed on a second conveyor, the second conveyordifferent from the first conveyor.

Step 17 optionally includes wetting the first separator and/or thesecond separator. The wetting can be via a wetting agent. In someembodiments, the wetting agent can include an electrolyte solventwithout electrolyte salt. In some embodiments, the wetting agent caninclude an electrolyte solution. In some embodiments, the wetting agentcan include a diluted electrolyte solution (i.e., an electrolytesolution with a salt concentration lower than the targeted saltconcentration in the finished electrochemical cell). In someembodiments, the wetting agent can have an electrolyte saltconcentration of at least about 0.1 M, at least about 0.2 M, at leastabout 0.3 M, at least about 0.4 M, at least about 0.5 M, at least about0.6 M, at least about 0.7 M, at least about 0.8 M, or at least about 0.9M. In some embodiments, the wetting agent can have an electrolyte saltconcentration of no more than about 1 M, no more than about 0.9 M, nomore than about 0.8 M, no more than about 0.7 M, no more than about 0.6M, no more than about 0.5 M, no more than about 0.4 M, no more thanabout 0.3 M, no more than about 0.2 M. Combinations of theabove-referenced concentrations of electrolyte salt in the wetting agentare also possible (e.g., at least about 0.1 M and no more than about 1 Mor at least about 0.4 M and no more than about 0.6 M), inclusive of allvalues and ranges therebetween. In some embodiments, the wetting agentcan have an electrolyte salt concentration of about 0.1 M, about 0.2 M,about 0.3 M, about 0.4 M, about 0.5 M, about 0.6 M, about 0.7 M, about0.8 M, about 0.9 M, or about 1 M.

In some embodiments, the electrolyte solvent can include ethyl methylcarbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC),dimethyl carbonate (DMC), butylene carbonate, and their chlorinated orfluorinated derivatives, and/or a family of acyclic dialkyl carbonateesters, such as dimethyl carbonate, diethyl carbonate, ethylmethylcarbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propylcarbonate, dibutyl carbonate, butylmethyl carbonate, butylethylcarbonate and butylpropyl carbonate. In some embodiments, theelectrolyte solvent can include gamma-Butyrolactone (GBL),dimethoxyethane, tetrahydrofuran, 2-methyl tetrahydrofuran,1,3-dioxolane, 1,4-dioxane, 4-methyl-1,3-dioxolane, diethyl ether,sulfolane, methylsulfolane, acetonitrile, propiononitrile, ethylacetate, methyl propionate, ethyl propionate, dimethyl carbonate,tetraglyme, monoglyme, dioxane, or any other suitable electrolytesolvent. In some embodiments, the electrolyte salt can include LiClO₄,LiPF₆, LiBF₄, LiTFSI, LiBETI, LiBOB, Lithium difluoro(oxalato)borate(LIODFB), Lithium bis(fluorosulfonyl)imide (LiFSI), or any otherappropriate electrolyte salt.

In some embodiments, the wetting agent can be sprayed onto the firstseparator and/or the second separator. In some embodiments, the wettingagent can be brushed onto the first separator and/or the separator. Insome embodiments, the wetting agent can be applied to the firstseparator via a first method and the second separator via a secondmethod, the second method different from the first method. In someembodiments, the wetting agent can aid in adhering the separators totheir respective electrode materials.

In some embodiments, less than about 20%, less than about 19%, less thanabout 18%, less than about 17%, less than about 16%, less than about15%, less than about 14%, less than about 13%, less than about 12%, lessthan about 11%, less than about 10%, less than about 9%, less than about8%, less than about 7%, less than about 6%, less than about 5%, lessthan about 4%, less than about 3%, less than about 2%, or less thanabout 1% by volume of the wetting agent can be lost to evaporationduring execution of the method 10.

In some embodiments, less than about 20%, less than about 19%, less thanabout 18%, less than about 17%, less than about 16%, less than about15%, less than about 14%, less than about 13%, less than about 12%, lessthan about 11%, less than about 10%, less than about 9%, less than about8%, less than about 7%, less than about 6%, less than about 5%, lessthan about 4%, less than about 3%, less than about 2%, or less thanabout 1% by volume of the electrolyte solution in the anode material canbe lost to evaporation during execution of the method.

In some embodiments, less than about 20%, less than about 19%, less thanabout 18%, less than about 17%, less than about 16%, less than about15%, less than about 14%, less than about 13%, less than about 12%, lessthan about 11%, less than about 10%, less than about 9%, less than about8%, less than about 7%, less than about 6%, less than about 5%, lessthan about 4%, less than about 3%, less than about 2%, or less thanabout 1% by volume of the electrolyte solution in the cathode materialcan be lost to evaporation during execution of the method.

In some embodiments, less than about 20%, less than about 19%, less thanabout 18%, less than about 17%, less than about 16%, less than about15%, less than about 14%, less than about 13%, less than about 12%, lessthan about 11%, less than about 10%, less than about 9%, less than about8%, less than about 7%, less than about 6%, less than about 5%, lessthan about 4%, less than about 3%, less than about 2%, or less thanabout 1% by volume of the combination of the electrolyte solution in theanode material, the electrolyte solution in the cathode material, andthe wetting agent can be lost to evaporation during execution of themethod.

In some embodiments, the anode material, the anode current collector,and the first separator can be disposed in a first package as an anodekit. In some embodiments, the cathode material, the cathode currentcollector, and the second separator can be disposed in a second packageas a cathode kit. In some embodiments, the first separator can be wettedprior to disposal in the first package. In some embodiments, the secondseparator can be wetted prior to disposal in the second package.

Step 18 includes coupling the first separator to the second separator toform the electrochemical cell. In some embodiments, the coupling caninclude adhering the first separator to the second separator. In someembodiments, the first separator and/or the second separator can bewetted to facilitate the adhering of the first separator to the secondseparator. In some embodiments, the anode material, the anode currentcollector, and the first separator can be removed from the first packageprior to coupling the first separator to the second separator to formthe electrochemical cell. In some embodiments, the cathode material, thecathode current collector, and the second separator can be removed fromthe second package prior to coupling the first separator to the secondseparator. In some embodiments, a semi-solid electrode material can beapplied to the first separator and/or the second separator prior tocoupling the first separator to the second separator, such that thesemi-solid electrode material is disposed between the first separatorand the second separator in the electrochemical cell. In someembodiments, a conventional electrode material can be applied to thefirst separator and/or the second separator prior to coupling the firstseparator to the second separator, such that the conventional electrodematerial is disposed between the first separator and the secondseparator in the electrochemical cell. In some embodiments, asolid-state electrolyte material can be applied to the first separatorand/or the second separator prior to coupling the first separator to thesecond separator, such that the solid-state electrolyte material isdisposed between the first separator and the second separator in theelectrochemical cell.

FIGS. 4A-4C show conveyance of electrodes, according to variousembodiments. FIGS. 4A-4C show an anode material 410 disposed on an anodecurrent collector 420 and being conveyed by a first conveyor 90 a, and acathode material 430 disposed on a cathode current collector 440 andbeing conveyed by a second conveyor 90 b. FIG. 4A shows the electrodeswithout any separators disposed thereon. As shown in FIG. 4A,electrolyte solvent ES evaporates from both of the electrodes. FIG. 4Bshows a first separator 450 a disposed on the anode material 410. Asshown in FIG. 4B, electrolyte solvent ES evaporates from the cathodematerial 430 but evaporation of electrolyte solvent ES from the anodematerial 410 is eliminated or significantly reduced. FIG. 4B shows thefirst separator 450 a disposed on the anode material 410 and a secondseparator 450 b disposed on the cathode material 430. As shown in FIG.4C, evaporation of electrolyte solvent ES from both the anode material410 and the cathode material 430 is eliminated or significantly reduced.As shown, the first conveyor 90 a is a separate conveyor from the secondconveyor 90 b. In some embodiments, the anode material 410, the anodecurrent collector 420, the cathode material 430, and the cathode currentcollector 440 can all be conveyed on the same conveyor.

FIG. 5 shows an illustration of an electrochemical cell 500, accordingto an embodiment. The electrochemical cell 500 is substantially similarto the electrochemical cell 200, and includes an anode material 510disposed on an anode current collector 520, a cathode material 530disposed on a cathode current collector 540, a first separator 550 adisposed on the anode material 510, and a second separator 550 bdisposed on the cathode material 530, which can be substantially similarto the anode material 210, the anode current collector 220, the cathodematerial 230, the cathode current collector 240, the first separator 250a, and the second separator 250 b, respectively, as previously describedherein with respect to the electrochemical cell 200.

However, different from electrochemical cell 200, the electrochemicalcell 500 also includes a third separator 550 c disposed between thefirst separator 550 a and the second separator 550 b. A first interlayer560 a is disposed between the first separator 550 a and the thirdseparator 550 c, and a second interlayer 560 b is disposed between thesecond separator 550 b and the third separator 550 c. The thirdseparator 550 c may be substantially similar to the first separator 250a and/or the second separator 250 b as described in detail with respectto the electrochemical cell 200.

In some embodiments, the first interlayer 560 a and/or the secondinterlayer 560 b can include an electrolyte layer, as described indetail with respect to FIG. 0.2. In some embodiments, the electrolytelayer can partially or fully saturate the first separator 550 a, thesecond separator 550 b, and or the third separator 550 (collectivelyreferred to as the separators 550). In some embodiments, the electrolytelayer can aid in bonding the first separator 550 a and second separator550 b to the third separator 550 c. In some embodiments, the electrolytelayer can create a surface tension to bond the first separator 550 a andthe second separator 550 b to the third separator 550 c. In someembodiments, the electrolyte layer can facilitate movement ofelectroactive species between the anode material 510 and the cathodematerial 530.

In some embodiments, the first interlayer 560 a and/or the secondinterlayer 560 b can have any thickness as described in detail withrespect to the interlayer 260 of the electrochemical cell 200. In someembodiments, the first interlayer 560 a and the second interlayer caninclude a semi-solid electrode layer disposed between the firstseparator 550 a and third separator 550 c, and the second separator 550b and the third separator 550 c, respectively. In some embodiments, thelayer of semi-solid electrode material can be included in addition tothe electrolyte layer. In some embodiments, the semi-solid electrodelayer between the first separator 550 a and the third separator 550 c,and/or between the second separator 550 b and the third separator 550 ccan include a material that reacts with metallic lithium. In someembodiments, the semi-solid electrode layer between the first separator550 a and the third separator 550 c, and/or between the second separator550 b and the third separator 550 c can include hard carbon, graphite,or any other suitable electrode material or combinations thereof. Insome embodiments, if the anode material 510 begins to form dendritesthat penetrate the first separator 550 a, the dendritic material canreact with the semi-solid electrode layer between the first separator550 a and the third separator 550 b, such that the dendrites dissipate,thus preventing a short circuit. In some embodiments, one or more of thefirst separator 550 a, the second separator 550 b, and the thirdseparator 550 c may include solid-state electrolyte sheets.

In some embodiments, the semi-solid electrode layer can aid intransporting electroactive species across the separators 550, and/orprovide reduced tortuosity and better lithium ion diffusion compared toconventional electrode materials. The composition of the semi-solidelectrode layer(s) can be fine-tuned to facilitate ion movementtherethrough. In some embodiments, the semi-solid electrode layerbetween the first separator 550 a and third separator 550 c, and/orbetween the second separator 550 b and the third separator 550 c canhave catalytic effects to remove, dissolve, and/or corrode contaminatingmetal powders (e.g., iron, chromium, nickel, aluminum, copper). In suchcases, the semi-solid electrode layer(s) can serve as a metalcontamination removing buffer layer. In some embodiments, the semi-solidelectrode layer(s) can include a non-lithium ion semi-solid slurry withan aligned pore structure, a high surface area, and/or a diffusivestructure combined with an electrolyte. Such materials can includemetal-organic frameworks (MOFs), carbon black, an anode aluminum oxide(AAO) template, and/or silica. In such cases, the semi-solid electrodelayer(s) can serve as an electrolyte reservoir and/or an embedding basefor a dendrite-removing catalyst. Such materials can also improvecurrent distributions in the electrochemical cell 250. In someembodiments, the dendrite-removing catalyst can include a metal baseand/or a polymer base for the facilitation of redox reactions. In someembodiments, the dendrite-removing catalyst can include fluorine,sulfide, or any other suitable catalyst or combinations thereof. In someembodiments, the catalyst can include a base polymer coating mix or acarbon mix.

In some embodiments, the interlayers 560 a and/or 560 b can include aconventional (i.e., solid) electrode layer disposed between the firstseparator 550 a and the third separator 550 c, and/or the secondseparator 550 b and the third separator 550 c, respectively. In someembodiments, the conventional electrode layer between the respectiveseparators 550 can include a binder (e.g., a solid binder or a gelbinder).

In some embodiments, the interlayers 560 a and/or 560 b can include apolyolefin, a solid-state electrolyte sheet, and/or a polymerelectrolyte sheet. In some embodiments, the interlayers 560 a and/or 560b can include polyacrylonitrile (PAN), poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP), poly(methyl methacrylate)(PMMA), polyacrylic acid (PAA), polyethylene oxide (PEO), or anycombination thereof.

In some embodiments, the interlayers 560 a and/or 560 b can include acathode. In some embodiments, the cathode in the interlayers 560 aand/or 560 b can include lithium titanate (LTO), hard carbon (HC),and/or any other material with a high impedance connection. In someembodiments, the LTO can include an electron-conductive LTO, such asLi_(4+x)Ti₅O₁₂ and/or Li₄Ti₅O_(12−x). In some embodiments, theinterlayers 560 a and/or 560 b can include lithium iron phosphate (LFP)with a high impedance connection. The LFP can be considered a safechemistry for the monitoring of dendrite formation. If a dendrite formsin either of the electrodes and penetrates into the interlayers 560 aand/or 560 b, the dendrite would be consumed. Also, voltage can bemonitored between the first interlayer 560 a and the anode currentcollector 520, as shown. In some embodiments, voltage can be monitoredbetween the second interlayer 560 b and the cathode current collector540. This voltage monitoring can detect if a dendrite has reached theinterlayers 560 a and/or 560 b.

Measuring voltage between the first interlayer 560 a and the anodecurrent collector 520 and/or the second interlayer 560 b and the cathodecurrent collector 540 can be a more efficient method of detectingdefects in the electrochemical cell 500 than measuring across the entireelectrochemical cell 500 (i.e., between the anode current collector 520and the cathode current collector 540), particularly in modules withmultiple cells. In some embodiments, multiple electrochemical cells canbe connected in parallel and/or series to produce a cell module. Forexample, if a cell has a capacity of 3 Ah, 50 such cells can beconnected in parallel to produce a capacity of 150 Ah. In someembodiments, the module can include about 1, about 2, about 3, about 4,about 5, about 6, about 7, about 8, about 9, about 10, about 11, about12, about 13, about 14, about 15, about 16, about 17, about 18, about19, about 20, about 25, about 30, about 35, about 40, about 45, about50, about 55, about 60, about 65, about 70, about 75, about 80, about85, about 90, about 95, or about 100 electrochemical cells connected inseries and/or parallel, inclusive of all values and ranges therebetween.In monitoring the voltage across the first interlayer 560 a and theanode current collector 520 and/or the second interlayer 560 b and thecathode current collector 540, the first interlayer 560 a and/or thesecond interlayer 560 b can serve as a reference electrode.

In some embodiments, individual electrochemical cell in a module canhave a capacity of about 0.5 Ah, about 1 Ah, about 2 Ah, about 3 Ah,about 4 Ah, about 5 Ah, about 6 Ah, about 7 Ah, about 8 Ah, about 9 Ah,or about 10 Ah, inclusive of all values and ranges therebetween. In someembodiments, modules described herein can have a capacity of about 10Ah, about 20 Ah, about 30 Ah, about 40 Ah, about 50 Ah, about 60 Ah,about 70 Ah, about 80 Ah, about 90 Ah, about 100 Ah, about 110 Ah, about120 Ah, about 130 Ah, about 140 Ah, about 150 Ah, about 160 Ah, about170 Ah, about 180 Ah, about 190 Ah, about 200 Ah, about 210 Ah, about220 Ah, about 230 Ah, about 240 Ah, about 250 Ah, about 260 Ah, about270 Ah, about 280 Ah, about 290 Ah, or about 300 Ah, inclusive of allvalues and ranges therebetween.

In some embodiments, only one of the first interlayer 560 a and thesecond interlayer 560 b may be connected or coupled to an electricalsource or sink. For example, in some embodiments, the first interlayer560 a (e.g., a graphite layer, a hard carbon layer, or any othermaterial described herein) may not be connected with cathode, neutral,or ground, while the second interlayer 560 b (e.g., a graphite layer, ahard carbon layer, or any other material described herein) may becoupled or connected to a cathode or neutral (e.g., via a diode or highresistance). In some embodiments, a current collector of any other layermay extend between the first separator 550 a and the second separator550 b to serve as the third separator 550 c, any may be employed as ashutdown separator. In some embodiments, the current collector of theother layer may be formed from aluminum, gold, platinum, stainlesssteel, titanium foil, conductive ink, etc. In some embodiments, thecurrent collector may be formed or processed by lamination, printing(e.g., inkjet printing, gravure printing, screen printing, etc.),sputtering, spray coating, or deposition, or any other suitable methodon the separator or any other suitable method. In some embodiments, atab may be coupled to the current collector that forms one of theinterlayers 560 a/b, or directly to the interlayer 560 a or 560 b thatdoes include a current collector (e.g., a graphite or hard carbonlayer). In other embodiments, the tab may be formed monolithically withthe current collector or otherwise interlayer 560 having a portionthereof disposed outside the electrochemical cell 500.

FIG. 6 shows an illustration of an electrochemical cell 600, accordingto an embodiment. The electrochemical cell 600 is substantially similarto the electrochemical cell 200, and includes an anode material 610disposed on an anode current collector 620, a cathode material 630disposed on a cathode current collector 640, a first separator 650 adisposed on the anode material 610, a second separator 650 b disposed onthe cathode material 630, and an interlayer 660 disposed between thefirst separator 650 a and the second separator 650 b. In someembodiments, the anode material 610, the anode current collector 620,the cathode material 630, the cathode current collector 640, and theinterlayer 660 can be the same or substantially similar to the anodematerial 210, the anode current collector 220, the cathode material 230,the cathode current collector 240, and the interlayer 260, as describedabove with reference to FIG. 2. Thus, certain aspects of the anodematerial 610, the anode current collector 620, the cathode material 630,the cathode current collector 640, and the interlayer 660 are notdescribed in greater detail herein.

Different from the electrochemical cell 200, the first separator 650 aand/or the second separator 650 b may include multiple layers. Forexample, as shown in FIG. 6, the first separator 650 a includes a firstseparator first layer 650 a 1 and a first separator second layer 650 a 2that are formed from different materials (e.g., any of the materialsdescribed with respect to the separators 260 a and 260 b). Similarly,the second separator 650 b includes a second separator first layer 650 b1 and a second separator second layer 650 b 2 that are formed fromdifferent materials (e.g., any of the materials described with respectto the separators 260 a and 260 b). The first separator second layer 650a 2 and the second separator second layer 650 b 2 is disposed proximateto the interlayer 660 such that the interlayer 660 is interposed betweenthe first separator second layer 650 a 2 and the second separator secondlayer 650 b 2. The interlayer 660 may include a semisolid interlayer,may include a binder, or may include any other interlayer as describedwith respect to the interlayer 260. In some embodiments, the firstseparator first layer 650 a 1 and the second separator first layer 650 b1 may be formed from polypropylene. In some embodiments, the firstseparator second layer 650 a 2 and the second separator second layer 650b 2 may be formed from polyethylene. In other embodiments, the firstseparator first and/or second layers 650 a 1 and 650 a 2, and/or thesecond separator first and second layers 650 b 1 and/or 650 b 2 may beformed from any other material as described herein. In some embodiments,axial end regions 670 of the first separator 650 a and/or the secondseparator 650 b that extend beyond an axial extent of the interlayer 660may be bonded, adhered, welded, or otherwise coupled to each other so asto form a sealed pocket or cavity within which the interlayer 660 isdisposed. This may advantageously prevent a semisolid or slurry basedinterlayer 660 from leaking from between the first separator 650 a andthe second separator 650 b.

FIG. 7 shows an illustration of an electrochemical cell 700, accordingto an embodiment. The electrochemical cell 700 is substantially similarto the electrochemical cell 200, and includes an anode material 710disposed on an anode current collector 720, a cathode material 730disposed on a cathode current collector 740, a first separator 750 adisposed on the anode material 710, a second separator 750 b disposed onthe cathode material 730, and an interlayer 760 disposed between thefirst separator 750 a and the second separator 750 b. In someembodiments, the anode material 710, the anode current collector 720,the cathode material 730, the cathode current collector 740, the firstseparator 750 a and the second separator 750 b can be the same orsubstantially similar to the anode material 210, the anode currentcollector 220, the cathode material 230, the cathode current collector240, the first current collector 250 a, and the second collector 250 b,as described above with reference to FIG. 2. Thus, certain aspects ofthe anode material 710, the anode current collector 720, the cathodematerial 730, the cathode current collector 740, the first separator 750a, and the second separator 750 b are not described in greater detailherein.

In some embodiment, the interlayer 760 is a multilayer structure. Forexample, as shown in FIG. 7, the interlayer 760 includes a first layer760 a that may include a solid-state electrolyte, for example, any ofthe solid-state electrolytes as described with respect to FIG. 2. Theinterlayer 760 may optionally, also include a second layer 760 bdisposed between the first layer 760 a and the first separator 750 a,and a third layer 760 c disposed between the first layer 760 a and thesecond separator 750 b. In some embodiments, the second layer 760 band/or the third layer 760 c may include a cathode, for example, LTO,hard carbon, LFP, and/or any other material with a high impedanceconnection, as described in detail with respect to FIG. 2. For example,the second layer 760 b may include hard carbon, and the third layer 760c may include LFP. The second layer 760 b may be coupled to the anodecurrent collector 720 via a first discharge protection component 780 a(e.g., a diode, a high resistance resistor, or any other suitablestructure) and the third layer 760 c may be coupled to the cathodecurrent collector 740 via a second discharge protection component 780 b(e.g., a diode, a high resistance resistor, or any other suitablestructure). As previously described, an iron dendrite can grow and touchhard carbon, graphite, and/or other carbon-containing materials in theinterlayer 760, with the interlayer 760 having an anode potential in thesecond layer 760 b and a cathode potential in the third layer 760 c.Once the iron dendrite touches the hard carbon, graphite, and/or theother carbon-containing materials in the interlayer 760, the irondissolves under the cathode potential, but the high current movingthrough the electrochemical cell 700 persists via a connection throughthe discharge protection components 780 a and 780 b. When metalcontamination is used to prevent dangerous short circuit events, voltagecan be monitored between the interlayer 760 and the anode currentcollector 720 and/or the cathode current collector 740, as describedwith respect to FIG. 2.

EXAMPLES

Comparative Example 1: A lithium-copper cell was constructed (referredto herein as “Comp Ex 1”). Lithium was plated onto copper foil. The cellwas cycled at 1 mA/cm² for 1 hour at 25° C. under a pressure of 200psig. Stripping of the copper foil continued until a 1V cut-off wasreached. A standard separator including a single layer (i.e., a singleseparator) was placed between the lithium foil anode and the copper foilcathode.

Example 1: A lithium-copper cell was constructed (referred to herein as“Ex 1”). Lithium was plated onto copper foil. The cell was cycled at 1mA/cm² for 1 hour at 25° C. under a pressure of 200 psig. Stripping ofthe copper foil continued until a 1V cut-off was reached. A separatorcoated with a layer of hard carbon (Kuraray HC, 2-3 μm) was coupled to astandard separator and placed between the lithium foil anode and thecopper foil cathode, the hard carbon layer facing the anode. The hardcarbon coated separator was implemented as a means of lithiating and/orcomplexing with any dendritic lithium that protrudes from the lithiumfoil surface, enabling a safety feature to prevent a hard short fromlithium plating on the anode.

Both Comp Ex 1 and Ex 1 were subject to 32 cycles before deconstruction,where lithium was stripped from the copper foil, allowing lithium tocomplex with the hard carbon in the Ex 1 cell. The hard carbon in theactive area of lithium appeared shiny, indicating lithiation of the hardcarbon. The hard carbon that was outside of the lithium foil contactarea was dull in color, suggesting it was unlithiated. The cycledlithium foil anode also appeared pristine in nature, indicating thelithium was being plated on the hard carbon. No mossy or dendriticlithium was observed on the foil. FIG. 8A-8B show supporting voltageprofiles highlighting the difference in overpotential of Comp Ex 1 (FIG.8A) vs. Ex 1 (FIG. 8B). As shown, Ex 1 with a hard carbon layer betweentwo separators, experiences less significant overpotential losses thanComp Ex 1.

Comparative Example 2: A lithium copper cell was constructed (referredto herein as “Comp. Ex. 2”) and operated similar to Comp. Ex. 1, exceptthat Comp. Ex. 2 was cycled at 7.5 mA/cm² with 75% lithium ion usage.

Example 2: A lithium copper cell was constructed (referred to herein as“Ex. 2”) and operated similar to Ex. 1, except that Ex. 2 was cycled at7.5 mA/cm² with 75% lithium ion usage. FIGS. 9A and 9B show supportingvoltage profiles highlighting the difference in overpotential of Comp.Ex. 2 and Ex. 2. The Comp. Ex. 2 cell that did not include theinterlayer shorted in 11 cycles within 22 hours, while the Ex. 2 cellthat included the hard carbon interlayer continued to operate normallyafter 25 cycles with minimum over polarization. This indicates that theinterlayer smooths or levels the current distribution for fast lithiumplating, storing, and preventing the dendrite from projecting throughthe separators.

As used in this specification, the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, the term “a member” is intended to mean a singlemember or a combination of members, “a material” is intended to mean oneor more materials, or a combination thereof.

The term “substantially” when used in connection with “cylindrical,”“linear,” and/or other geometric relationships is intended to conveythat the structure so defined is nominally cylindrical, linear or thelike. As one example, a portion of a support member that is described asbeing “substantially linear” is intended to convey that, althoughlinearity of the portion is desirable, some non-linearity can occur in a“substantially linear” portion. Such non-linearity can result frommanufacturing tolerances, or other practical considerations (such as,for example, the pressure or force applied to the support member). Thus,a geometric construction modified by the term “substantially” includessuch geometric properties within a tolerance of plus or minus 5% of thestated geometric construction. For example, a “substantially linear”portion is a portion that defines an axis or center line that is withinplus or minus 5% of being linear.

As used herein, the term “set” and “plurality” can refer to multiplefeatures or a singular feature with multiple parts. For example, whenreferring to a set of electrodes, the set of electrodes can beconsidered as one electrode with multiple portions, or the set ofelectrodes can be considered as multiple, distinct electrodes.Additionally, for example, when referring to a plurality ofelectrochemical cells, the plurality of electrochemical cells can beconsidered as multiple, distinct electrochemical cells or as oneelectrochemical cell with multiple portions. Thus, a set of portions ora plurality of portions may include multiple portions that are eithercontinuous or discontinuous from each other. A plurality of particles ora plurality of materials can also be fabricated from multiple items thatare produced separately and are later joined together (e.g., via mixing,an adhesive, or any suitable method).

As used herein, the term “semi-solid” refers to a material that is amixture of liquid and solid phases, for example, such as a particlesuspension, a slurry, a colloidal suspension, an emulsion, a gel, or amicelle.

Various concepts may be embodied as one or more methods, of which atleast one example has been provided. The acts performed as part of themethod may be ordered in any suitable way. Accordingly, embodiments maybe constructed in which acts are performed in an order different thanillustrated, which may include performing some acts simultaneously, eventhough shown as sequential acts in illustrative embodiments. Putdifferently, it is to be understood that such features may notnecessarily be limited to a particular order of execution, but rather,any number of threads, processes, services, servers, and/or the likethat may execute serially, asynchronously, concurrently, in parallel,simultaneously, synchronously, and/or the like in a manner consistentwith the disclosure. As such, some of these features may be mutuallycontradictory, in that they cannot be simultaneously present in a singleembodiment. Similarly, some features are applicable to one aspect of theinnovations, and inapplicable to others.

In addition, the disclosure may include other innovations not presentlydescribed. Applicant reserves all rights in such innovations, includingthe right to embodiment such innovations, file additional applications,continuations, continuations-in-part, divisional s, and/or the likethereof. As such, it should be understood that advantages, embodiments,examples, functional, features, logical, operational, organizational,structural, topological, and/or other aspects of the disclosure are notto be considered limitations on the disclosure as defined by theembodiments or limitations on equivalents to the embodiments. Dependingon the particular desires and/or characteristics of an individual and/orenterprise user, database configuration and/or relational model, datatype, data transmission and/or network framework, syntax structure,and/or the like, various embodiments of the technology disclosed hereinmay be implemented in a manner that enables a great deal of flexibilityand customization as described herein.

All definitions, as defined and used herein, should be understood tocontrol over dictionary definitions, definitions in documentsincorporated by reference, and/or ordinary meanings of the definedterms.

As used herein, in particular embodiments, the terms “about” or“approximately” when preceding a numerical value indicates the valueplus or minus a range of 10%. Where a range of values is provided, it isunderstood that each intervening value, to the tenth of the unit of thelower limit unless the context clearly dictates otherwise, between theupper and lower limit of that range and any other stated or interveningvalue in that stated range is encompassed within the disclosure. Thatthe upper and lower limits of these smaller ranges can independently beincluded in the smaller ranges is also encompassed within thedisclosure, subject to any specifically excluded limit in the statedrange. Where the stated range includes one or both of the limits, rangesexcluding either or both of those included limits are also included inthe disclosure.

The phrase “and/or,” as used herein in the specification and in theembodiments, should be understood to mean “either or both” of theelements so conjoined, i.e., elements that are conjunctively present insome cases and disjunctively present in other cases. Multiple elementslisted with “and/or” should be construed in the same fashion, i.e., “oneor more” of the elements so conjoined. Other elements may optionally bepresent other than the elements specifically identified by the “and/or”clause, whether related or unrelated to those elements specificallyidentified. Thus, as a non-limiting example, a reference to “A and/orB”, when used in conjunction with open-ended language such as“comprising” can refer, in one embodiment, to A only (optionallyincluding elements other than B); in another embodiment, to B only(optionally including elements other than A); in yet another embodiment,to both A and B (optionally including other elements); etc.

As used herein in the specification and in the embodiments, “or” shouldbe understood to have the same meaning as “and/or” as defined above. Forexample, when separating items in a list, “or” or “and/or” shall beinterpreted as being inclusive, i.e., the inclusion of at least one, butalso including more than one, of a number or list of elements, and,optionally, additional unlisted items. Only terms clearly indicated tothe contrary, such as “only one of” or “exactly one of,” or, when usedin the embodiments, “consisting of,” will refer to the inclusion ofexactly one element of a number or list of elements. In general, theterm “or” as used herein shall only be interpreted as indicatingexclusive alternatives (i.e., “one or the other but not both”) whenpreceded by terms of exclusivity, such as “either,” “one of,” “only oneof” or “exactly one of.” “Consisting essentially of,” when used in theembodiments, shall have its ordinary meaning as used in the field ofpatent law.

As used herein in the specification and in the embodiments, the phrase“at least one,” in reference to a list of one or more elements, shouldbe understood to mean at least one element selected from any one or moreof the elements in the list of elements, but not necessarily includingat least one of each and every element specifically listed within thelist of elements and not excluding any combinations of elements in thelist of elements. This definition also allows that elements mayoptionally be present other than the elements specifically identifiedwithin the list of elements to which the phrase “at least one” refers,whether related or unrelated to those elements specifically identified.Thus, as a non-limiting example, “at least one of A and B” (or,equivalently, “at least one of A or B,” or, equivalently “at least oneof A and/or B”) can refer, in one embodiment, to at least one,optionally including more than one, A, with no B present (and optionallyincluding elements other than B); in another embodiment, to at leastone, optionally including more than one, B, with no A present (andoptionally including elements other than A); in yet another embodiment,to at least one, optionally including more than one, A, and at leastone, optionally including more than one, B (and optionally includingother elements); etc.

In the embodiments, as well as in the specification above, alltransitional phrases such as “comprising,” “including,” “carrying,”“having,” “containing,” “involving,” “holding,” “composed of,” and thelike are to be understood to be open-ended, i.e., to mean including butnot limited to. Only the transitional phrases “consisting of” and“consisting essentially of” shall be closed or semi-closed transitionalphrases, respectively, as set forth in the United States Patent OfficeManual of Patent Examining Procedures, Section 2111.03.

While specific embodiments of the present disclosure have been outlinedabove, many alternatives, modifications, and variations will be apparentto those skilled in the art. Accordingly, the embodiments set forthherein are intended to be illustrative, not limiting. Various changesmay be made without departing from the spirit and scope of thedisclosure. Where methods and steps described above indicate certainevents occurring in a certain order, those of ordinary skill in the arthaving the benefit of this disclosure would recognize that the orderingof certain steps may be modified and such modification are in accordancewith the variations of the invention. Additionally, certain of the stepsmay be performed concurrently in a parallel process when possible, aswell as performed sequentially as described above. The embodiments havebeen particularly shown and described, but it will be understood thatvarious changes in form and details may be made.

1. A method of forming an electrochemical cell, the method comprising:disposing an anode material onto an anode current collector; disposing afirst separator on the anode material; disposing a cathode material ontoa cathode current collector; disposing a second separator onto thecathode material; and disposing the first separator on the secondseparator to form the electrochemical cell, wherein at least one of theanode material or the cathode material is a semi-solid electrodematerial including an active material, a conductive material, and avolume of liquid electrolyte; and wherein less than about 10% by volumeof the liquid electrolyte evaporates during the forming of theelectrochemical cell.
 2. The method of claim 1, further comprising:wetting at least one of the first separator or the second separator withan electrolyte solution prior to disposing the first separator on thesecond separator.
 3. The method of claim 2, wherein wetting the at leastone of the first separator and the second separator is via spraying. 4.The method of claim 2, wherein less than about 10% by volume of theelectrolyte solution evaporates during the forming of theelectrochemical cell.
 5. The method of claim 4, wherein less than about10% of a total volume of a combination of the electrolyte solution andthe liquid electrolyte evaporates during the forming of theelectrochemical cell.
 6. The method of claim 1, wherein at least one ofthe first separator or the second separator is composed of a materialwith a porosity of less than about 1%.
 7. The method of claim 1, whereinthe cathode current collector, the cathode material, and the secondseparator collectively form a cathode, the method further comprising:conveying the cathode along a conveyor.
 8. The method of claim 7,wherein the anode current collector, the anode material, and the firstseparator collectively form an anode, and wherein the conveyor is afirst conveyor, the method further comprising: conveying the anode alonga second conveyor.
 9. The method of claim 7, wherein the anode currentcollector, the anode material, and the first separator collectively forman anode, the method further comprising: conveying the anode along theconveyor.
 10. The method of claim 1, wherein the semi-solid electrodematerial is a first semi-solid electrode material, the method furthercomprising: disposing a second semi-solid electrode material between thefirst separator and the second separator.
 11. The method of claim 10,further comprising: measuring a voltage between the second semi-solidelectrode material and at least one of the anode current collector orthe cathode current collector.
 12. A method of forming anelectrochemical cell, the method comprising: disposing a semi-solidcathode material onto a cathode current collector, the semi-solidcathode material including an active material, a conductive material,and a volume of non-aqueous liquid electrolyte, disposing an anodematerial onto an anode current collector; disposing a first separator onthe semi-solid cathode; disposing a second separator on the anodematerial; dispensing an electrolyte solution on at least one of thefirst separator or the separator; and disposing the first separator onthe second separator to form an electrochemical cell.
 13. The method ofclaim 12, wherein less than about 10% by volume of the non-aqueousliquid electrolyte evaporates during the forming of the electrochemicalcell.
 14. The method of claim 12, wherein dispensing the electrolytesolution is via spraying.
 15. The method of claim 12, wherein less thanabout 10% of a total volume of a combination of the electrolyte solutionand the non-aqueous liquid electrolyte evaporates during the forming ofthe electrochemical cell.
 16. The method of claim 12, wherein theelectrolyte solution includes a solid-state electrolyte.
 17. The methodof claim 12, wherein at least one of the first separator or the secondseparator has a porosity of less than about 1%.
 18. The method of claim12, wherein the cathode current collector, the cathode material, and thesecond separator collectively form a cathode and the anode currentcollector, the anode material, and the first separator collectively forman anode, the method further comprising: conveying at least one of thecathode or the anode along a conveyor.
 19. An electrochemical cell,comprising: an anode disposed on an anode current collector, the anodeincluding an anode active material and an anolyte; a cathode disposed ona cathode current collector, the cathode including a cathode activematerial and a catholyte; a first separator disposed on the anode, thefirst separator composed of a first material and having a firstporosity; and a second separator disposed on the cathode, the secondseparator composed of a second material and having a second porosity,the second porosity different from the first porosity.
 20. Theelectrochemical cell of claim 19, wherein the second material isdifferent from the first material.
 21. The electrochemical cell of claim20, wherein the second material includes a polyimide and the firstmaterial includes polyethylene.
 22. The electrochemical cell of claim21, wherein the anolyte includes ethylene carbonate and propylenecarbonate.
 23. The electrochemical cell of claim 19, wherein the firstseparator physically contacts the second separator.
 24. Theelectrochemical cell of claim 19, further comprising an interlayerdisposed between the first separator and the second separator, theinterlayer including at least one of a semi-solid electrode material, asolid electrode material, or a solid-state electrolyte.
 25. Theelectrochemical cell of claim 24, wherein the interlayer includes asemi-solid electrode material.
 26. The electrochemical cell of claim 24,wherein the interlayer includes lithium titanate (LTO) and the cathodeincludes NMC.
 27. The electrochemical cell of claim 24, wherein theinterlayer includes lithium iron phosphate (LFP) and the cathodeincludes NMC.